In the field of dental treatment, a resin material called resin composite is used for restoring a decayed tooth of a relatively light degree. To restore the decayed tooth by using the resin composite, the decayed portion of the tooth is removed by grinding, the portion that is missing by grounding is pre-treated with an etching material, a cured layer of a curable composition called bonding material is formed thereon so as to exhibit a high adhesive property to the resin composite, and the resin composite is adhered onto the layer of the bonding material. As the bonding material, there can be used a liquid curable composition of either the photo-curing type or the chemical-curing type.
The dental material is contained in a container body made of a plastic. At the time of use, the container is pushed by fingertips to produce pressure in the container body so that the material falls down in drops from an ejection port.
Namely, the following document 1 discloses a liquid container of the one-push squeeze type according to which the container is held between the thumb and the forefinger or the middle finger to pressurize the liquid-containing chamber in the container so that the liquid in the liquid-containing chamber flows out in drops in a required amount from an opening at an end of the nozzle. Upon removing the pressure from the liquid-containing chamber, the liquid in the opening at the end of the nozzle is sucked into the container back due to the resilience force of the container. The liquid container of the squeeze type is simple in the structure permitting the liquid contained in the container chamber to fall down in drops from the opening at the end of the nozzle by simply pushing the container body and has, therefore, been frequently used as a container for containing the dental bonding materials.
Some dental materials are highly volatile. When the container body is gripped by hand, therefore, the temperature of the human body is conducted to the interior of the container body through the outer circumferential wall thereof, and the adhesive volatilizes due to an increase in the temperature and is often ejected more than necessary through the ejection port. In particular, the adhesive is often preserved in a refrigerator. When the adhesive is taken out from the refrigerator, therefore, the temperature may rise to a considerable degree to hinder its use.
Therefore, the container disclosed in the patent document 1 is provided with a separate bag-like envelope that surrounds the bottom portion and the body portion of the container body. In the envelope, gaps formed among the ribs extending in the up-and-down direction play the role of a heat-insulating material preventing a rise in the temperature in the container body and enabling the liquid to be dripped in a desired amount responsive to the operation by fingertips.
The following patent document 2 discloses a knock-type container that can be used as a writing instrument storing such a liquid as ink, Japan ink or paint, as a makeup article storing such a liquid as eye liner, lip color or manicure, as a medicine container storing such a liquid as eye lotion, antiseptic solution or antibiotic, or as an application instrument storing such a liquid as seasoning, machine oil or washing solution.
The knock-type ejection container has a brush ear of a circular shape in cross section at an ejection portion at an end thereof, and has a knock button at the other end thereof. Responsive to each push of the knock button, a piston member pressurizes the liquid in the reservoir chamber, and the liquid is pushed out to the brush ear. With the brush ear being soaked with the liquid, the liquid contained therein is applied at the time of use onto an object.
Like the patent document 1, the following patent document 3 discloses a liquid container of the one-push squeeze type according to which the container is held between the thumb and the forefinger or the middle finger to pressurize the liquid-containing chamber in the container so that the liquid in the liquid-containing chamber flows out in drops in a required amount from an opening at an end of the nozzle. Upon removing the pressure from the liquid-containing chamber, the liquid in the opening at the end of the nozzle is sucked into the container back due to the resilience force of the container. The liquid container of the squeeze type is simple in the structure permitting the liquid contained in the container chamber to flow down in drops from the opening at the end of the nozzle by simply pushing the container body and has, therefore, been frequently used as a container for containing the dental bonding materials.